Residential aquarium-keeping is an established industry in the United States and around the world. The most basic version of an aquarium consists of a transparent container for aquatic life to be viewed and housed within. These containers are typically constructed of either glass or a transparent plastic material such as acrylic or polystyrene but may be made of other transparent or semi-transparent materials. Basic aquatic environments of this nature are limited in their ability to sustain suitable conditions and water quality for all but a handful of robust and hearty fish. More appropriate for the health and well-being of the aquatic organisms is the addition of filtration, lighting, oxygenation, temperature control, and chemical and biological balance.
The need for temperature management of an aquarium varies significantly based on external environmental conditions as well as the species of aquatic animal or plant kept within the aquarium. Temperature is maintained by either adding heat to the aquarium when the water temperature is below what is desired or by chilling the water down to the “proper” or desirable temperature. In a condition in which heating is required, an external heating element is added to the tank to raise the temperature of the tank. These heating elements are fundamentally resistive heating elements contained within a waterproof plastic, glass, or metal housing. The heater is placed within the water chamber of the aquarium and contains thermal sensors/switches to raise the temperature of the water. There are a variety of control and temperature management systems, but all currently available heating elements contain an electrical wire that leads into the water column of the aquarium to connect a power supply with the heating element. These types of heating elements can be used on micro desktop aquariums of as little as 0.5 gallons up to aquariums containing hundreds of gallons of water.
Temperature management for cooling down an aquarium to a desired temperature is typically performed through external plumbing of the aquarium to a “chiller”. This is often done through external plumbing and “removal” of water from the aquarium to maintain water temperature. These external cooling systems often have a heating system included as well. These systems are most typical of large aquatic environments where the total water volume of the system exceeds 30 gallons or more, and more typically 55 gallons or more.
Lighting needs of an aquarium range from decorative to functional. In the simplest version, decorative lighting is a low intensity light either in or on the aquarium that is used to provide an aesthetic appeal to the consumer. Functional needs vary greatly and are dictated by the species present. Lighting used within the aquarium industry varies from incandescent, LED, fluorescent, metal halide and even plasma lighting. The major trends are towards LED lighting. In decorative in-tank lighting, the LED light is often coupled with an air-stone or other decor to provide an aesthetic appeal to the consumer. In these systems there is often a power cord for the light (or multiple power cords for lighting) as well as an air-tube that enters into the water column. In external lighting, the power cord attaches to a light that either is integrated into the tank or sits on its surface to illuminate the aquarium.
Chemical balance for an aquarium is essential to sustain life in the aquarium. Ammonia, nitrite and nitrate are toxic elements to fish and need to be properly maintained. Depending on the species of fish in the tank, proper balance of other chemicals is also critical to aquarium health. For example elements such as strontium, calcium, magnesium, phosphorus, iodine as well as the pH of the system require proper balance. In advanced systems, water chemistry can be continuously or periodically monitored to ensure proper balance. Some systems can even continuously balance these elements. Biological balance is important as nitrosomonas and nitrobacter bacteria species complete the nitrogen cycle and naturally transform Ammonia and nitrite to nitrate (the least toxic of the three to aquatic life).
Dissolved oxygen is a fundamental requirement for aquatic life. In most aquariums, oxygenation is maintained through transient surface agitation from filtration, normal gas exchange (if the load on the aquarium to surface area of the tank is not too high), or through addition of air through the system through airstones and an air pump.
The single most critical element to successful aquarium keeping is the aquarium filter. The aquarium filter has been around for over 40 years in some form or another. Filtration systems for aquariums include air filters, power filters, external sump filters, canister filters, hang on filters, “horizontal” above aquarium filters, internal filters and other specialized filtration (including ion exchange, skimmers, etc.). With the exception of specialized filtration, all other traditional filters serve the purpose of moving water through a filtration system to remove impurities from the aquarium. Current technology focuses almost exclusively on water pump driven filtration. In a water pump driven filtration system the water is actively (and mechanically) pushed or pulled through a filtration device that contains filtration media. The filtration system most typically incorporates a variety of filtration methods including mechanical (a coarse and sometimes fine filter material), chemical filtration (most typically activated carbon to treat chemical pollutants), and biological filtration (to allow naturally occurring bacteria to thrive and treat the water). In all water filtration systems the water is pumped from the aquarium into a mechanism that includes some or all of these filtration elements and then returns the water back into the aquarium. For best results the mechanical filtration should be either cleaned or replaced 1-2 times per month, the chemical filtration should be replaced 1-2 times per month, and the biological filtration should be left untouched.
Aquarium maintenance is derived from three elements. The first (and partially unnecessary element for aquarium health) is derived from consumer desire to keep an aesthetically “clean” aquarium. This often means removal of algae and detritus from the glass and décor surfaces. This maintenance can often be more problematic to the health of the aquarium than beneficial but is considered a necessary element of aquarium maintenance. This cleaning is beneficial when the maintenance cleans detritus and debris from the gravel/substrate itself. In time, these organic materials will break down into contaminants that can be harmful to fish.
The second element is to change the water of an aquarium. This should be done on a partial basis in order to maintain beneficial bacteria that reside in the aquarium. The purpose of doing a water change is to remove naturally occurring chemicals that build up in the aquarium (most critically nitrate) because of the nature of the artificial environment. The rate of buildup is determined based on fish load, plant load, and feeding load on the aquarium. This is highly variable and as such it is recommended that 20-25% of an aquarium be changed on a monthly basis. The effective dilution effect on contaminant level buildup when changed on this schedule has shown to, as a general rule of thumb, keep contaminant levels at healthy levels for the aquarium. In more advanced systems chemical balance incorporates additional maintenance (e.g., additions/resin exchange).
The third and final aquarium maintenance required is on the filtration system itself. Mechanical filtration needs to be either cleaned or replaced on at least a monthly basis and chemical filtration should be replaced on approximately a monthly or more frequent basis. It is these combined maintenance elements that both lead to the highest level of consumer frustration, and when not conducted properly, lead to unhealthy aquariums.
A water change is currently conducted in only one fashion. Water is “drawn” out of the aquarium effectively reducing the water volume in the aquarium by 15-100% and subsequently reducing the water height in the interior chamber of the aquarium by a proportionate amount. The desirable volume should be approximately 20-25% and can extend to as high as 50%, but misinformation and misunderstanding often lead to 100% water change by new consumers to the hobby. Depending on the size of the aquarium this water change is conducted by the following:
Moving the aquarium to a sink and pouring water out to a desired level. Due to weight constraints, this is typically only done on the smallest of aquariums (1-2 gallons and smaller). In order to perform this type of water change all electrical appliances in the aquarium must be removed or unplugged and transferred with the aquarium. There is further risk of disrupting décor, plants and fish through this transfer and pour.
Removing water from the aquarium “in place”. This is done by pumping, suctioning, siphoning or physically scooping water out of the tank. This method requires additional equipment not integral and is performed on most aquariums larger than 1-2 gallons. Water is then typically placed in a bucket or other transfer device to be added back to the aquarium. This method of conducting a water change requires external equipment not integral to the aquarium, often is cumbersome and timely to perform, and often times leaves a residual mess that requires further cleaning to complete the water change (for example water dripping on the floor, added buckets, tubes, pumps to clean and store). If not unplugged or performed with care, heating elements can be left exposed to the air during water changes of this nature. This can lead to failure of the heater itself which at minimum renders the heater useless and in a worst case scenario presents a major failure risk.
Filtration maintenance is often done at the same time as a water change but does not have to be. This requires removal of the filtration media (mechanical and chemical). In many current filtration systems these two elements are integrated into a single unit. In these systems the entire “cartridge” is disposed and replaced with a new cartridge. In other systems the mechanical and chemical cartridge or element are separate. In these systems the mechanical portion is either cleaned or replaced and the chemical media is replaced. In either scenario the consumer removes a wet element from the aquarium environment and needs to transport the wet, dirty, soiled cartridge to a sink for cleaning or garbage for disposal. In either case the cartridge either drips and drops contaminant onto the floor or counter top until it reaches its destination or some external device is used to prevent this from occurring (often a bucket, tub, paper towel, etc.). In all cases the consumer risks making a mess and/or having additional elements to clean upon completion of providing the maintenance to the filter.